Combustor with sectional housing and liner



April 3, 1951 B. o. BUCKLAND COMBUSTOR WITH SECTIONAL HOUSING 'AND LINER Filed Nov. 27. 1948 Ihveht or. Bruce O. Buckland,

His Attovn ey.

Patented Apr. 3, 1951 UNI'IE S l sans Fries CQMBUSTOR VVI'EH SECTKONAL HUSING AND LINER Bruce 0. Buckland, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application November 27, 1948, Serial No. 62,333

Howard, Chester S. Riie, and Bruce G. Buckland,

Serial No. 7541302, filed June l1, i947, and assigned to the sarne assignee as the present application..

The object of the present invention is to provide an. improved combustor for a` powerplant oi the type described having both the outer housing and the inner liner fabricated in separate sections so that a portion of the outer housing may be readily removed for free access to the inner liner sections for inspection, servicing, or replacement.

Other objects and advantages will be apparent fromy the following description taken in connection with the accompanying drawing in which Fig, 1 isa longitudinal view in section oi a gas turbine combustor incorporating the invention; Fig. 2 is a transverse sectional View of the combustor taken on the irregular plane 2-2 in Fig. 1; Fig.'3 is' a perspective View of one oi the' connecting devices used to. hold the liner sections in proper relation; While Fig. i is a detail View in section of another connecting device used between certain of the liner sections.

Referring now more particularly to Fig.A 1, 'the main frame of thejpowerpl'ant includes a cylindrical vframe member l secured by a bolted iiange at one end toa mid-frame casing 2. rCasing 2 is provided" with' a plurality oi radially extending lugs 3 which are welded to, or maybe cast integral with, a casing d dening transition passages connecting the annular discharge of an axial flow compressor (not shown) with the circumferentially spaced circular combustor1 inlet openings. The inlet end portion ofV the transition passage is indicated at ia while the cylindrical housing. ib defines one supporting wall for the outer combustor casing. To the other end of the main frame cylinder i is welded a transverse annular plate, member 5 having a plurality ofcircumeren'tially spaced circular openings tra there being one of these openings for each combustor of course. Each opening is surrounded by an axially extending cylinder welded to the plate 5 mitting ready access to and quick removal of the inner liner where the end sections which support the combustor are fixed rigidly to the main frame.

The outer combustor casing consists of a rst cylindrical section and a second section S. In

order to provide a gas-tight seal between the end of section i and the adjacent end of the cylindrical casing 4, a packing arrangement is provided including a stuffing box ring member 4c welded to the end oi casing 4b as shown in Fig. 1, a gland nut 9 threadedly received in the bore of the stufiing box 4c, and one or more resilient packing rings Iii contained. within the stuffing box ic surrounding the end portion oi liner section l and of course arranged to be compressed by the gland nut 9.

The other outer casinfr section 8 is likewise sealed in a stuiiing box. ring @a by a gland nut I l compressing packing rings` i2 into tight Contact with the outer surface of the adjacent portion of casing section 8. The adjacent endsl of outer casing sections 1 3 are connected by means of a pipe coupling including pair of anges I3, M welded to the respective ends of sections '1, 8, the flanges being clamped tightly together by means of a suitable clamp ban-d indicated generally at l5. This may consist ci a circumferential band split at least at one location with radially projecting ears adjacent the split, with a bolt or other suitable clamping device c-ooperating with the ears to draw the band circumferentially into tight engagement with they flangesA i3, it. This clamping device is indicated diagrammatically at i6. The details of the clamp band are not material to an understanding of the present invention., but it may be noted that a suitable type of clamp band structure is shown in the patent to W. D. Crater, 2,424,436-, issued July 22, 1947, and assigned to the same assignee as the present application.

Secured to the outer wall of the transition orV mid-frame casing i is a fuel nozzle indicated generally at il. The' details of this fuel spray nozzle are not material to an understanding of the present invention, being disclosed more fully' in the copending application of Bruce O. Buckland and Donald C. Berkey, Serial No. 62,634, filed November 3l), 1948,- andr assigned to the same assignee as the present application. it may be noted however, that this nozzle is of a type especially adapted to produce a spray pattern in the formv of a hollow cone lla, the vertex angle of which remains almost exactlyl constant over the entire range of operation.

The combustion space proper is dened by an inner' liner consisting of an end dome assembly I8, I9, which is supported in telescopic relation with succeeding'interme'diateliner sections 2B, 2 I

3 'and discharge end liner sections 22, 23 and a hot gas transition section 24.

The end dome proper, indicated generally at I8, is a substantially hemispherical shell made of a temperature resisting sheet metal such as stainless steel and having a central portion dening an opening adapted to -snugly receive the `nozzle tip I'lb. The right-hand end or" dome I8 is supported by mear-1s of a plurality of radially (extending .pins 25, which may be secured, as by vwelding, to the fend liner section I9 and project freely through holes in the dome I8. Thus, the fend dome I8 and the end -liner section |51 are {coaxially'located but may freely expand and contract relative to each other.

The end liner section I9 is in turn supported by a pair of iiexible brackets 26 located diametrically opposite as shown best in Fig. 2. These brackets each consist of an elliptical loop of flexible sheet metal having portions welded at 2 5a to the outer surface of liner section I9, while a second portion is secured by means of a suitable threaded fastening 2`| to the other wall 4b of the transition section. This resilient suspension likewise permits the end liner section I9 to expand and contract radially relative to the casing walls 4b. As may be seen in Figs. 1 and 2, the inlet of liner section I9 forms an air inlet shroud I9a surrounding the end dome I8 and having an annular end baffle |913 with perforations |9c for admitting a metered quantity of air to the space ISd between dome I8 and shroud Ia. A somewhat similar shroud arrangement is disclosed in the copending application of K. D. McMaha-n, Serial No. 705,866, led October 26, 1946, Patent No. 2,510,645, and assigned to the same assignee as the present application. Just outside the bale ISb, shroud Ia is provided with two or more circumferentially spaced projections, which may be in the form of short pins or tubes ISe extending loosely into sockets in bosses 4c formed integral with casing 4. These projections serve to locate the shroud I3a when the fuel nozzle I'I is removed.

The second liner section 20 is supported in proper coaxial relation with the end section I9 by a plurality of longitudinal keys, as follows. As may be more readily seen in Figs. 2 and 3, the initial liner section I9 has spotwelded thereto a plurality of circumferentially spaced prong members comprising a channel member 30 to which is welded, in backtoback relation, another axially extending channel member 3|. The cooperating portions of the second liner section 23 have welded thereto circumferentially spaced pairs of brackets 32. It will be apparent that the brackets 32 comprise a keyway while the channel member 3| constitutes a longitudinal key. As may be seen in Fig. 1, there is a substantial radial clearance between key member 3| and the adjacent outer surface of the liner section 20. As shown in Fig. 3, the sides of the channel 3| fit without clearance between the brackets 32. With this arrangement, the liner sections are accurately located concentrically, while being free to expand radially relative to each other, being also free to move longitudinally by reason of the key-and-keyway connection.

This locating means insures that the adjacent liner sections will be held exactly coaxial while freely permitting differential thermal expansion therebetween.

Section 20 is of suciently larger diameter than section I9 that a narrow radial clearance space is formed between the telescoping end portions, which clearance space serves as an aninular nozzle to direct a lm of cooling and insulating air along the inner surface of liner section 20 in the manner of the arrow 33. The sup- -port for the liner section 2U is provided by a pair of diametrically opposite flexible brackets 34, which are similar to the members 26 described above. It will be observed that the supporting brackets 34 are spaced 90 angularly from the brackets 26 of the rst liner section I9, while the similar brackets 35 supporting section 2| are again spaced from the brackets 34. Similarly, brackets 36 support the liner section 22 and are located in the same axial plane with the brackets 34.

As will be readily apparent from Fig. l, the righthand end of liner section 20 forms a keyand-keyway connection with the telescoping end portion of section 2|, in the manner described in connection with sections IS, 2D. Here again there is suiiicient clearance between the telescoping end portions that a thin annular rllm of cooling and insulating air is formed on the inner surface of the next section 2 I, as indicated by arrow 31. A similar key-and-keyway connection serves to support section 2| in telescopic relation with liner section 22. On the other hand, section 22 is located relative to section 23 by means of a pin-and-slot connection, comprising bracket members 38 ,spot-welded at 38a. (Fig. 4) to the outer surface of section 23 and projecting freely inwardly through slots 39 in section 22. This permits the section 22 to slide telescopically into the end section 23, for a purpose which will appear hereinafter.

Discharge end liner section 23 is supported on flexible brackets 40 and forms at its right-hand end a pin-and-slot connection with the inlet end of the transition section 24, by means of radially extending brackets 4I similar to the brackets 38. The transition section 24 projects freely through the opening 50. provided in p?ate 5, and changes from the circular section of the combustor exit to an arcuate discharge section indicated at 24a. These arcuate discharge portions 24a are of such circumferential extent that the several transition sections associated with the respective combustors together form a continuous 360 discharge annulus emptying into the nozzle ring assembly, a portion of which is illustrated diagrammatically at 42.

As will be understood to those familiar with the so-called Nerad type combustor, the combustor end dome I8 and the respective liner sections I9, 20, 2|, 22, 23, are provided with combustion air inlet holes arranged in a particular Way to obtain a peculiarly characteristic air ow pattern within the combustion space, as more particularly described in the copending application of Anthony J. Nerad, Serial No. 750,015, filed May 23, 1947, and assigned to the same assignee as the present application. As described fully in that application, the combustion air ows radially inward through the combustion air ports 45, some of this air meeting at the axis of the liner and flowing to the left as indicated bythe arrows 45a, while other portions flow to the right as indicated by the arrows 45h. The portion indicated by arrows 45a flows back towards the nozzle I1, where it entrains and vaporizes the fuel droplets in the spray cone IIa.v The burning fuel-air mixture then ows axially down the combustion space between the longitudinal rows of combustion air jets entering through theports 45. It may also be noted that theendA dome I8 wall and a second end portion located substantially in the plane of the intersection of the intermediate assembly with the discharge end liner assembly, a second cylindrical outer housing section surrounding in radially spaced relation the discharge end liner assembly, said second outer housing section having a first end portion adapted to be secured to the adjacent end of the first housing section and a second end portion adapted to be secured to the open end of the second supporting wall, said discharge end liner assembly comprising a cylindrical section arranged within the second supporting wall and flexibly supported therefrom in radially spaced relation and another cylindrical liner section adapted to slide telescopically into the first-mentioned end liner section, means flexibly securing said second-mentioned end liner section to the second outer housing section in radially spaced relation therewith. means exibly securing said intermediate liner assembly to the first outer housing section in radially spaced relation, first fastening means securing the end of the iirst outer housing section to the adjacent end of the rst supporting wall, second fastening means securing the end of the second outer housing section to the adjacent end of the second supporting wall, and third fastening means securing togetherl the adjacent ends of said first and second outer housing sections, the relative dimensions of the inner liner sections and outer housing sections being so related to the frame and supporting Walls that with said first, second, and third fastening means removed the second outer housing section v may slide telescopically into the second support wall whereupon the iirst outer housing section with the intermediate liner section attached may be removed as a unit from the space dened between the respective open ends of said supporting Walls.

2. In a combustor for a thermal powerplant having a frame, a iirst substantially cylindrical combustor support wall xed to the frame and defining a circular end opening, a second substantially cylindrical combustor support wall xed to the frame and substantially coaxial with and having an open end axially spaced from and facing the open end of the first wall, an end dome assembly comprising a wall or substantially circular cross section having a closed end defining a central opening adapted to receive fuel injection means and a second open end located substantially in the plane of the open end of the first support wall, means supporting the end dome assembly within and in radially spaced relation to the first support wall, a first intermediate assembly comprising a first substantially cylindrical outer housing section and an intermediate liner assembly supported within radially spaced relation thereto, said intermediate liner assembly having a rst end portion adapted to surround the adjacent end or the end dome assembly in telescopically slidable relation therewith and a second open end portion located substantially in the plane of the adjacent end of the first outer housing section, a discharge end liner section located within and xed to the second support wall in radially spaced relation and having a circular open end portion substantially in the plane of the open end of the second support wall, a second intermediate assembly including a second cylindrical outer housing section adapted to slide axially in telescopic relation into the second support wall and having an end portion adapted to be secured to the adjacent end of the rst outer housing section, and a second intermediate inner liner section supported from the second outer housing seLtion in radially spaced relation therewith and having a rst end portion adapted to surround in telescopically slidable relation the adjacent end of the iirst intermediate liner assembly, said second intermediate liner section having a second end portion adapted to enter the adjacent end of the discharge liner section in telescopically slidable relation, means fas.- tening the adjacent ends of the rst and second outer housing sections together and other means for fastening the opposite ends of the outer housing sections tc said rst and second supporting walls respectively, the dimensions of said supporting walls, inner liner sections, and outer housing sections being so related that with said fastening means removed the second intermediate assembly may be moved axially into the second support wall whereupon the first intermediate aslsembly may be moved axially toward the second support wall and then removed transversely through the space dened between said support walls thus giving free access to the end dome assembly and the discharge end section.

3. In a combustor for a thermal powerplant having a frame with a first combustor support wall dening a circular open end portion and a second substantially cylindrical support wall fixed to the frame in coaxial relation with the iirst wall and having an open end portion facing and axially spaced from the open end of the first wall, the combination of an inner liner assembly dening an elongated substantially cylindrical reaction space and comprising an end dome assembly located within and coaxial with the first supporting wall and defining at one end a central opening adapted to receive fuel injecting means, said dome assembly having at the other end a cylindrical open end portion, means resiliently supporting the end dome assembly from the rst supporting wall whereby differential thermal expansion in a radial direction may freely occur therebetween, an intermediate liner assembly having at one end a portion surrounding the adjacent open end of the dome assembly in telescopically slidable relation therewith, and a discharge end liner assembly having one end portion surrounding the adjacent end of the intermediate liner assembly in telescopically slidable relation therewith and forming at the other end a discharge opening for hot reaction products, an outer combustor housing including a rst cylindrical section surrounding the intermediate linerassembly in radially spaced relation therewith and having a rst end portion adapted to be secured to the open end of the first supporting wall and a second end portion located substantially in the plane of the intersection of the intermediate assembly with the discharge end liner assembly, said first end portion of the first outer housing sect'on being slidably arranged relative to the rst support wall and having packing means therebetween, the combustor outer housing including also a second cylindrical outer section surrounding the discharge end liner assembly in radially spaced relation therewith and having a first end porton adapted to be secured to the adjacent end ofthe first outer housing section and a second end portion slidably received in the second supporting wall and having packing means therebetween, said discharge end liner assembly comprising la cylindrical section arranged Within the second supporting wall and resiliently supported therefrom in radially spaced relation and anothercy'-, lindrical liner section arranged within and resiliently supported from the second outer housing section and adapted to slide telescopically into the first-mentioned discharge end liner section, readily removable fastening means securing the discharge end liner sections to the second outer housing section and to the second support wall respectively, readily removable fastening means securing the intermediate liner assembly tothe first outer` housing section, and readily removable fastening means securing the end dome assembly in said first support wall, retainer means associated with the first outer housing section and the first support Wall for preventing accidental relative axial movement therebetween, readily removable pipe coupling means securing together the adjacent ends of the outer housing sections, the relative dimensions of the inner liner sections and outer housing sections being so related to each other and to the supporting walls that with said retainer means and pipe coupling means removed the second outer housing section may slide telescopically into the second support wall carrying the discharge end liner sections therewith, whereupon the first outer housing section with the intermediate liner section attached may be removed as a unit from the space defined between the respective open ends lof said supporting walls.

4. In a combustor for a thermal powerplant having a frame with a first support wall with a circular open end portion and a second substantially cylindrical support wall iixed to the frame in coaxial relation With said first wall and having an open end portion facing and axially spaced from the open end of the first wall, the combination of an inner liner assembly defining an elongated substantially cylindrical reaction space and comprising an end dome assembly located Within and coaxial with the first supporting Wall and defining at one end a central opening adapted to receive fuel injecting means with the other end open for the discharge of reaction products, readily removable fastening means resiliently supporting the end dome assembly within the rst supporting Wall in radially spaced relation thereto whereby differential thermal expansion in a radial direction may freely occur therebetween, an intermediate liner assembly having at one end a portion surrounding the adjacent open end portion of the dome assembly in telescopically slidable relation therewith, and a discharge end liner assembly having one end portion surrounding the adjacent end of the intermediate liner assembly in telescopically slidable relation therewith and forming at the other end a discharge opening for hot reaction products, an outer housing including a first cylindrical section surrounding the intermediate liner assembly and having a first end portion adapted to be. secured to the open end of the first supporting wall and a second end portion located substantially in the plane of the intersection of the intermediate liner assembly with the discharge end liner assembly, a second cylindrical outer housing section, surrounding the discharge end liner assembly, said second outer housing section having a first end portion adapted to be secured to the adjacent end of the first outer housing section and'a second end portion adapted to be sealed to the open end of the second supporting wall, readily removable means iiexibly supporting said intermediate liner assembly in radially spaced relation within the iii-st outer housing section, readily removable fastening means resiliently securing the discharge end liner assembly in radially spaced rela- 10 tion Within the second outer housing section. first retainer means securing the end of the first outer housing section to the adjacent end of the iirst sup-porting wall, pipe coupling means connecting the adjacent end portions of the first and second outer housing sections, and releasable packing means associated with said second support wall and the adjacent portion of the second outer housing section, the relative dimensions of theinner liner sections and outer housing sections being so related to the frame and supporting Walls that, with the retainer means and pipe coupling means removed and the packing means released, the second outer housing section with the discharge end liner assembly attached may slide telescopically into the second support wall whereupon the first outer housing section with the intermediate liner section attached may be removed as a unit from the space defined between the respective open ends of said supporting walls.

5. In a combustion device of the type described, means for supporting adjacent liner sections in concentric, radially spaced, telescopic relation including a bracket member secured to the outer surface of the inner liner section at a' location spaced axially from the forward end of the inner section and having a radially extending portion terminating in an axially extending member dening a key arranged longitudinally of the section, said axially extending key member being spaced radially from the outer surface of the outer liner section, .and bracket means secured to the outer surface of the outer liner section and dening a longitudinally disposed keyway adapted to receive the key portion of said firstmentioned bracket with comparatively close circumferential clearances but appreciable radial clearance whereby radial expansion of one liner section relative to the other is freely permitted While concentricity is maintained accurately, the liner sections being at the same time free to slide axially relative to each other for purpose of disassembly.

6. .'in a combustion device of the type described, means for supporting the adjacent liner sections in concentric, radially spaced, telescopic relation including a bracket member secured to the'outer surface of one liner section at a location spaced axially from the end of the section and having a radially extending portion terminating in an axially extending member defining a key arranged longitudinally of the sections, said key member overlying and spaced radially from the outer surface of the other liner section, and other bracket means secured to the outer surface of the other section and defining a longitudinalli7 disposed keyway adaptedto receive the key portion of said first-mentioned bracket With substantially no circumferential clearance but appreciable radial clearance, whereby radial expansion of one liner section relative to the other is freely permitted while concentricity is maintained accurately, the liner sections being at the same time free to slide axially relative to each other for assembly and disassembly.

BRUCE o. BUCKLAND.

REFERENCES CITED UNITED STATES PATENTS Name Date Seippel Dec. 30, 1941 Number 

